This study explores the effect of transfusion of fresh frozen plasma or the complement inactivated and immunoglobulin-depleted plasma protein derivative, Plasmanate, on serum opsonic activity for gram negative bacteria and on complement activity in both classical and alternative pathways. Preliminary studies demonstrate decreased complement and opsonin activity in the sera of some patients on admission. Nutritional rehabilitation reverses the defect, but not until two or more weeks of treatment. Fresh frozen plasma, but not Plasmanate, improves opsonin and complement function and complement levels after transfusion. No alterations in transferrin, alpha-l-acid glycoprotein, alpha-2-macroglobulin, or immunoglobulins A, M or G result from either transfusion. The present phase of study will determine the effect of multiple transfusion, and the decay in activity thereafter, especially during the first week of the study.